Over the last few decades, a growing number of studies have been investigating how the concentration and/or stock of soil organic matter varies across spatial scales ranging from the nano to landscape, regional, and global scales. However, relatively little is known about what kind of changes in SOM composition or stability accompany the observed spatial variability of SOM concentrations. This session will explore this important topic that is key for our understanding of the fate and transformation of organic matter in the soil system, and land to water fluxes of both dissolved and particulate forms of OM. We welcome submissions that probe issues related to inherent spatial variability of SOM quantity, quality, and their implications for SOM persistence, including, but not limited to, works that investigate the role of human activities, lateral transport by erosion, fire, changes in climate or hydrological flow regimes, etc.